Teachers, and school administrators as well as audiologists and otolaryngologists are being asked by parents whether a cochlear implant would be of help to their profoundly deaf child. Because of the devastating effect profound deafness has on the acquisition of speech the primary question is "Will a cochlear implant help my child learn to talk?" The extraordinary expense of cochlear implants, financially as well as emotionally in terms of the parents' investment of hope, necessitates establishing an objective basis for recommending an implant. At the present time this decision is influenced by empathy for children so deaf they do not benefit from hearing aids as well as parental and professional expectations of positive results. These expectations are based largely on successful experiences reported by postlingually deafened adults. Results obtained so far on prelingually deaf children with single-channel implants are not as promising, particularly with regard to their development of spoken language. The proposed investigations are intended to determine objectively whether cochlear electrical stimulators (CES), tactile aids (TA), acoustic hearing aids (AHA) or some combination of these are best for developing spoken language in prelingual profoundly deaf children. One study will compare improvements in comprehension and production of spoken language for 20 children fitted with cochlear implants in relation to 20 matched children with tactile aids and 20 with hearing aids. All 60 children will be enrolled in the same intensive oral training program. This will permit examination of the effects of these devices over and above gains normally achieved as a result of oral instruction. A single subject design will be used to examine improvements in speech perception and speech production within the same child when a CES or TA is worn compared to periods in which the device is removed or turned off. The anticipated outcomes of this project include: 1) Specification of improvements in speech perception and speech production ability which may be anticipated with a tactile aid or cochlear implant over conventional amplification; 2) Comparison of the long term advantage of each device in promoting the acquisition of spoken language and intelligible speech in the prelingually profoundly deaf child; 3) Recommendations regarding selection of the most effective device and training program for specific categories of profoundly deaf children; 4) Recommendations for an appropriate battery of tests for evaluating device effectiveness.